Hi,
I need some information about poly(dεA) and I can’t find any answers in the net. I’m testing the capacity of a protein to bind to ssDNA using poly(dεA). I know how to obtain poly(dεA) but what is the difference between poly(dA) and poly(dεA)? Why does fluorescence get bigger when the protein interacts with ssDNA?

Chloroacetaldehyde forms an adduct across the 1,N6 atoms of adenosine and can do something similar across the 3,N4 atoms of cytosine. When they made these things back in the 1970s and early 1980s, they knew that the modified base had intrinic fluorescence, but they didn’t know about the enhancement on binding to proteins; that they discovered in the mid 1980s. I haven’t seen any good explanation as to why the fluorescence increases on binding. My guess is that adjacent adducts (or other bases, even) quench the intrinsic fluorescence of the adduct. Binding to protein disrupts the interbase interactions and thus enhances the fluorescence by removing the quenching. I have no idea if that is in fact what happens, though.

I don't know if this will work or not, but I've attached a word file with the chemical structure of 1,N6-adenine.

Hm. Apparently not.

Biochemistry (1972) 11: 3499 if you want to see the structure of the adduct.